Display unit, method of manufacturing the same, and electronic apparatus

ABSTRACT

A display unit of the present disclosure includes: a plurality of pixels configured to emit emission light different from one another; and an insulating film provided between the plurality of pixels and having a reflective surface with respect to the emission light, in which an angle of the reflective surface of the insulating film is set for each of the pixels.

CROSS REFERENCES TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 14/771,557, filed on Aug. 31, 2015, which application is aNational Stage Entry of PCT Application No. PCT/JP2014/055675, filed onMar. 5, 2014, which application claims priority from Japanese PatentApplication No. 2013-058492, filed on Mar. 21, 2013, the content ofwhich is hereby incorporated by reference into this application.

TECHNICAL FIELD

The present disclosure relates to a display unit that emits light withuse of an organic electroluminescence (EL) phenomenon, a method ofmanufacturing the same, and an electronic apparatus including the same.

BACKGROUND

As development of information and communications industry has beenaccelerated, display devices having high performance have been demanded.In particular, an organic EL device that has attracted attention as anext-generation display device has advantages, as a self-luminousdisplay device, of not only a wide viewing angle and excellent contrastbut also fast response speed.

The organic EL device (light-emitting device) has a configuration inwhich a plurality of layers including a light-emitting layer arelaminated. More specifically, the organic EL device may be configuredof, for example, a wiring layer connected to a TFT that controls drivingof the light-emitting device, an anode that injects holes, thelight-emitting layer, a cathode that injects electrons, a resin, a colorfilter layer, and a pixel separation layer. The light-emitting deviceemits light by injecting holes and electrons from the anode and thecathode, respectively, to the light-emitting layer and recombining theholes and the electrons. One of the anode and the cathode sandwichingthe light-emitting layer therebetween also acts as a reflective mirrorto produce an interference effect different according to a lightemission angle or a wavelength. Therefore, light emission intensity ofthe light-emitting device greatly differs by the light emission angleand the wavelength.

For example, in a case where the light emission angle is large, emissionlight propagates in a device, and is not allowed to exit from a panel.Therefore, for example, in Patent Literature 1, there is disclosed adisplay unit in which component light leaked to an insulating film isreturned an organic layer with use of a laminate of optical films of twokinds having different refractive indices from each other as insulatingfilms that separate a plurality of light-emitting devices from oneanother. Moreover, in Patent Literature 2, there is disclosed a displayunit in which an optical distance of a light-emitting device including aresonance section is set for each device.

CITATION LIST Patent Literature

-   Patent Literature 1: Japanese Unexamined Patent Application    Publication No. 2010-153127-   Patent Literature 1: Japanese Unexamined Patent Application    Publication No. 2006-30250

SUMMARY

However, in the display unit in Patent Literature 1, there is an issuethat even though light emission efficiency is improved, colorreproductivity varies according to the viewing angle. Moreover, in thedisplay unit in Patent Literature 2, there is an issue that even thoughcolor reproductivity is improved, a manufacturing process iscomplicated.

Therefore, it is desirable to provide a display unit that is able toimprove color productivity by a simple method and to suppress variationin luminance, a method of manufacturing the same, and an electronicapparatus.

A display unit according to an embodiment of the present technologyincludes: a plurality of pixels configured to emit emission lightdifferent from one another; and an insulating film provided between theplurality of pixels and having a reflective surface with respect to theemission light, in which an angle of the reflective surface of theinsulating film is set for each of the pixels.

A method of manufacturing a display unit according to an embodiment ofthe present technology includes: arranging a plurality of pixelsconfigured to emit emission light different from one another; andforming, between the plurality of pixels, an insulating film having areflective surface with respect to the emission light and in which anangle of the reflective surface is set for each of the pixels.

An electronic apparatus according to an embodiment of the presenttechnology includes the above-described di splay unit.

In the display unit, the method of manufacturing the same, and theelectronic apparatus according to the embodiments of the presenttechnology, the insulating film having a reflective surface is providedbetween the pixels, and the insulating film is so formed as to set theangle of the reflective surface of the insulating film for each pixel;therefore, emission light with high light emission intensity in eachpixel is allowed to be reflected to an arbitrary direction.

According to the display unit, the method of manufacturing the same, andthe electronic apparatus of the embodiments of the present technology,the insulating film is so formed as to set the reflective surface anglethereof for each pixel; therefore, the emission direction of emissionlight with high light emission intensity in each pixel is adjusted.Accordingly, color reproductivity of each pixel is allowed to beimproved. Moreover, variation in light emission luminance in each pixelis allowed to be suppressed.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a plan view illustrating a configuration of a display unitaccording to an embodiment of the present disclosure.

FIG. 2 is a sectional view illustrating an example of one pixel of thedisplay unit illustrated in FIG. 1.

FIG. 3A is a schematic view illustrating an optical path of emissionlight in a display unit according to a comparative example.

FIG. 3B is a characteristic diagram illustrating a relationship betweena viewing angle and luminance of the display unit illustrated in FIG.3A.

FIG. 4A is a schematic view illustrating an optical path of emissionlight in the display unit illustrated in FIG. 1.

FIG. 4B is a characteristics diagram illustrating a relationship betweena viewing angle and luminance of the display unit illustrated in FIG. 1.

FIG. 5 is a sectional view illustrating another example of one pixel ofthe display unit illustrated in FIG. 1.

FIG. 6 is a diagram illustrating a configuration of the display unitillustrated in FIG. 1.

FIG. 7 is a diagram illustrating an example of a pixel drive circuit ofthe display unit illustrated in FIG. 6.

FIG. 8A is a sectional view for describing an example of a method ofmanufacturing the display unit illustrated in FIG. 1.

FIG. 8B is a sectional view illustrating a process following FIG. 8A.

FIG. 8C is a sectional view illustrating a process following FIG. 8B.

FIG. 9 is a sectional view illustrating another example of the method ofmanufacturing the display unit illustrated in FIG. 1.

FIG. 10A is a sectional view of a display unit according to ModificationExample 1.

FIG. 10B is a plan view of the display unit illustrated in FIG. 10A.

FIG. 11 illustrates examples of pixel shapes (A) to (D) according toModification Example 2.

FIG. 12 is an example of a plan view illustrating a configuration of adisplay unit using the pixel shape (C) illustrated in FIG. 11.

FIG. 13A is a characteristic diagram illustrating changes in viewingangle and luminance in a comparative example.

FIG. 13B is a characteristic diagram illustrating changes in viewingangle and luminance in Example 1 of the present disclosure.

FIG. 14A is a characteristic diagram illustrating changes in viewingangle and luminance in a comparative example.

FIG. 14B is a characteristic diagram illustrating changes in viewingangle and luminance in Example 2 of the present disclosure.

FIG. 15A is a characteristic diagram illustrating changes in viewingangle and luminance in a comparative example.

FIG. 15B is a characteristic diagram illustrating changes in viewingangle and luminance in Example 3 of the present disclosure.

FIG. 16 is a characteristic diagram illustrating changes in viewingangle and luminance in Example 4 of the present disclosure.

FIG. 17A is a perspective view illustrating an appearance on a frontside of Application Example 1 of the display units using the pixelaccording to the above-described embodiment and the like.

FIG. 17B is a perspective view illustrating an appearance on a back sideof Application Example 1 of the display units using the pixel accordingto the above-described embodiment and the like.

FIG. 18 is a perspective view illustrating an appearance of ApplicationExample 2.

FIG. 19A is a perspective view illustrating an appearance viewed from afront side of Application Example 2.

FIG. 19B is a perspective view illustrating an appearance viewed from aback side of Application Example 2.

FIG. 20 is a perspective view illustrating an appearance of ApplicationExample 3.

FIG. 21 is a perspective view illustrating an appearance of ApplicationExample 4.

FIG. 22A is a front view, a left side view, a right side view, a topview, and a bottom view in a state in which Application Example 5 isclosed.

FIG. 22B is a front view and a side view in a state in which ApplicationExample 5 is opened.

DETAILED DESCRIPTION

Some embodiments of the present disclosure will be described below indetail with reference to the accompanying drawings. It is to be notedthat description will be given in the following order.

1. Embodiment

1-1. Basic Configuration

1-2. Entire Configuration of Display Unit

1-3. Manufacturing Method

1-4. Functions and Effects

2. Modification Examples

Modification Example 1 (An example in which an aperture ratio isadjusted for each pixel)

Modification Example 2 (Examples of a pixel shape)

Modification Example 3 (An example in which reflectivity of aninsulating film is adjusted)

3. Examples

4. Application Examples (Examples of Electronic Apparatus)

1. EMBODIMENT

FIG. 1 illustrates an example of a planar configuration of a displayunit (a display unit 1A) according to an embodiment of the presentdisclosure. This display unit 1 A is used for a finder of a camera, ahead mounted display, or the like, and may have a configuration in whicha plurality of pixels 2 are arranged in dots in a display region 110.Each of the pixels 2 may be configured of sub-pixels of three colors,i.e., a red pixel 2R, a green pixel 2G, and a blue pixel 2B, and thesub-pixels 2R, 2G, and 2B include light-emitting devices generatingsingle-color light corresponding thereto (a red light-emitting device10R generating single-color light of red (for the red pixel 2R), a greenlight-emitting device 10G generating single-color light of green (forthe green pixel 2G), and a blue light-emitting device 10B generatingsingle-color light of blue (for the blue pixel 2B), respectively) (allrefer to FIG. 2).

(1-2. Basic Configuration)

FIG. 2 illustrates a sectional configuration of one pixel 2 illustratedin FIG. 1. The pixel 2 is configured of sub-pixels of three colors,i.e., the red pixel 2R, the green pixel 2G, and the blue pixel 2B asdescribed above, each of which has a light emission region partitionedby an insulating film 13 (13RG, 13GB, and 13BR). Here, the lightemission region of each of the sub-pixels 2R, 2G, and 2B may have, forexample, a circular shape as illustrated in FIG. 1.

The insulating film 13 is a so-called partition wall that electricallyseparates the light-emitting devices 10R, 10G, and 10B from one another,and is provided with an opening section 13A as a light emission regionin each of the sub-pixels 2R, 2G, and 2B. As will be described in detaillater, an organic layer 14 that includes a light-emitting layer 14C (ared light-emitting layer 14CR, a green light-emitting layer 14CG, or ablue light-emitting layer 14CB) configuring corresponding one of thelight-emitting devices 10R, 10G, and 10B is provided in the openingsection 13A. Examples of a material of the insulating film 13 mayinclude, but not be limited to, organic materials such as polyimide, anovolac resin, and an acrylic resin, and, for example, a combination ofan organic material and an inorganic material may be used. Examples ofthe inorganic material may include SiO₂, SiO, SiC, and SiN. Theinsulating film 13 may be formed, for example, as a single-layer filmmade of the above-described organic material. In a case where theorganic material and the inorganic material are combined, a laminatedconfiguration of an organic film and an inorganic film may be adopted.

A sectional surface of the insulating film 13 may have, for example, atrapezoidal shape or a rectangular shape, and a side surface of theinsulating film 13 serves as a reflective surface with respect toemission light LR, LG, and LB emitted from the light-emitting layers14CR, 14CG, and 14CB. The emission light LR, LG, and LB is reflected bythis reflective surface, and may be emitted upward, for example, asindicated by alternate long and short dash lines illustrated in FIG. 2.

In this embodiment, as illustrated in FIG. 2, the insulating film 13 hasa reflective surface angle (θ) set for each of side surfaces by whichthe red pixel 2R, the green pixel 2G, and the blue pixel 2B areenclosed. Herein, the reflective surface angle (θ) may be, for example,an angle that a top surface of a first electrode 12 forms with the sidesurface of the insulating film 13, and may be, for example, from 45° to90° both inclusive.

Emission light from each of the light-emitting layers 14CR, 14CG, and14CB produces an interference effect different according to a lightemission angle and a wavelength. Therefore, a light emission directionof light with high light emission intensity differs according to each ofthe light-emitting devices 10R, 10G, and 10B. FIG. 3A schematicallyillustrates a sectional configuration of a typically used display unit100 and emission light LR, LG, and LB from light-emitting devices 110R,110G, and 110B. It is to be noted that a solid line indicates light withhigh light emission intensity of the emission light LR, LG, and LB and abroken line indicates light with low light emission intensity of theemission light LR, LG, and LB.

In the display unit 100, insulating films 113 provided between thelight-emitting devices 110R, 110G, and 110B are formed uniformly. Inother word, the insulating films 113 provided between the light-emittingdevices 110R, 110G, and 110B are so formed as to allow reflectivesurface angles (θ) thereof to be equal to one another. As describedabove, light emitted from each of light-emitting layers 114CR, 114CG,and 114CB of the light-emitting devices 110R, 110G, and 110B has lightemission intensity different according to the wavelength. Therefore, asillustrated in FIG. 3A, emission light emitted from each of thelight-emitting layers 114CR, 114CG, and 114CB (so-called light with highlight emission intensity and light with low light emission intensity) isreflected by a reflective surface of the insulating film 113 to adirection different according to each wavelength. Accordingly, a colorshift in a viewing angle between the light-emitting devices 110R, 110G,and 110B, and variation in luminance illustrated in FIG. 3B occur.

FIG. 4A schematically illustrates emission directions of emission lightLR, LG, and LB in the display unit 1A of this embodiment. In thisembodiment, as described above, an inclination angle of the insulatingfilm 13 serving as a reflective surface with respective to the emissionlight LR, LG, and LB, i.e., a reflective surface angle (θ) is set foreach of the sub-pixels 2R, 2G, and 2B. Therefore, as illustrated in FIG.4A, light with high light emission intensity of the emission light LR,LG, and LB is emitted to the substantially the same direction. In otherwords, as illustrated in FIG. 4B, the light-emitting devices 10R, 10G,and 10B have substantially uniform viewing angle characteristics. Thus,a color shift between the sub-pixels 2R, 2G, and 2B and variation inluminance are eliminated.

It is to be noted that an optimum reflective surface angle (θ) of theinsulating film 13 with respect to the emission light LR, LG, and LBvaries according to not only a wavelength of emission light that is tobe reflected but also film thicknesses of the first electrode 12 and theorganic layer 14 including the light-emitting layer 14C that configureeach light-emitting device 10 and materials of the respective layers.Therefore, when a sample is formed by calculating an approximate value(θ) of the reflective surface angle (θ) in each of the light-emittingdevices 10R, 10G, and 10B with use of the following expression (1) wherean angle at which light emission intensity is strong is ϕ, and then thereflective surface angle (θ) of each insulating film 13 is furtheradjusted, it is possible to further reduce the color shift by theviewing angle.(Mathematical Expression)θ=90−ϕ/2(°)  (1)

As with this embodiment, the insulating film 13 having the reflectivesurface angle (θ) different for each of the sub-pixels 2R, 2G, and 2Bmay be formed by photolithography with use of, for example, aphotosensitive resin, as will be described in detail later. Morespecifically, it is possible to form an arbitrary reflective surfacewith use of a photomask having light transmittance varying in a stepwisemanner or a photoresist pattern for processing that is adjusted to acorresponding side wall angle in combination with typical dry etching.

It is to be noted that, in this embodiment, the reflective surface ofthe insulating film 13 is adjusted to an optimum angle for each of thered pixel 2R, the green pixel 2G, and the blue pixel 2B; however, thereflective surface angle (θ) of the insulating film 13 may be sodesigned as to allow the reflective surface angles for two of thesub-pixels to be equal to each other. More specifically, for example, aswith a display unit 1B illustrated in FIG. 5, the reflective surfaceangles (θ) for a red pixel 3R and a blue pixel 3B may be equal to eachother, and the reflective surface angle (θ) of the insulating film 13may be designed for the red pixel 3R and the blue pixel 3B and for agreen pixel 3G to adjust the emission direction of each emission light.Higher color reproductivity is obtained when the reflection angle is setfor each of the pixels 3R, 3G, and 3B; however, even if the reflectivesurface angles (θ) for two of the three sub-pixels are adjusted to beequal to each other, color reproductivity is sufficiently improved.Moreover, it is possible to further simplify formation of the reflectivesurface angle of the insulating film 13.

Further, in FIG. 2, a state in which a top surface of the insulatingfilm 13 is horizontal to a drive substrate 10 is illustrated; however,this embodiment is not limited thereto, and the top surface of theinsulating film 13 may have asperities or a curved surface. Furthermore,the thickness of the insulating film 13 may be larger than that of thefirst electrode 12, and may be preferably a thickness at which light ina planar direction of emission light from the light-emitting layer 14Cis allowed to be reflected to, for example, a top surface direction.More specifically, a distance from the top surface of the firstelectrode 12 to the top surface of the partition wall 13 may be 1 ormore. It is to be noted that an upper limit of the distance may bepreferably, but not particularly limited to, equal to or less than, forexample, a pixel size.

(1-2. Entire Configuration of Display Unit)

FIG. 6 illustrates a configuration of the display unit 1A. As describedabove, this display unit 1 A is used as a small-to-medium-sized displayunit such as a finder of a camera including organic EL devices as thelight-emitting devices 10R, 10G, and 10B, and may include, for example,a signal line drive circuit 120 and a scanning line drive circuit 130 asdrivers for image display around the display region 110.

A pixel drive circuit 140 is provided in the display region 110. FIG. 7illustrates an example of the pixel drive circuit 140. The pixel drivecircuit 140 is an active drive circuit formed below the first electrode12 that will be described later. In other words, the pixel drive circuit140 includes a driving transistor Tr1 and a writing transistor Tr2, acapacitor (a retention capacitor) Cs between the transistors Tr1 andTr2, and the light-emitting device 10R (or 10G or 10B) connected inseries to the transistor Tr1 between a first power supply line (Vcc) anda second power supply line (GND). Each of the driving transistor Tr1 andthe writing transistor Tr2 is configured of a typical thin filmtransistor, and the thin film transistor may have, for example, but notexclusively, an inverted stagger configuration (a so-called bottom gatetype) or a stagger configuration (a top gate type).

In the pixel drive circuit 140, a plurality of signal lines 120A arearranged along a column direction, and a plurality of scanning lines130A are arranged along a row direction. An intersection of each signalline 120A and each scanning line 130A corresponds to one (one sub-pixel)of the light-emitting devices 10R, 10G, and 10B. Each of the signallines 120A is connected to the signal line drive circuit 120, and animage signal is supplied from the signal line drive circuit 120 to asource electrode of the writing transistor Tr2 through the signal line120A. Each of the scanning lines 130A is connected to the scanning linedrive circuit 130, and a scanning signal is sequentially supplied fromthe scanning line drive circuit 130 to a gate electrode of the writingtransistor Tr2 through the scanning line 130A.

As illustrated in FIG. 2, each of the light-emitting devices 10R, 10G,and 10B includes the first electrode 12 as an anode, the insulating film13, the organic layer 14 including the light-emitting layer 14C, and asecond electrode 15 as a cathode that are laminated in this order fromthe drive substrate 11 provided with the driving transistor Tr1 of theabove-described pixel drive circuit 140 and a planarization insulatingfilm (not illustrated). The driving transistor Tr1 is electricallyconnected to the first electrode 12 through a connection hole (notillustrated) provided in the planarization insulating film.

Such light-emitting devices 10R, 10G, and 10B are covered with aprotective layer 16, and a sealing substrate 19 is bonded onto theentire protective layer 16 with an adhesive layer 17 in between. It isto be noted that the sealing substrate 19 includes a color filter 18Aand a black matrix 18B, and in the color filter 18A, color filters (ared filter 18AR, a green filter 18AG, and a blue filter 18AB) ofcorresponding colors are provided on the light-emitting devices 10R,10G, and 10B, respectively. The protective layer 16 may be made ofsilicon nitride (SiN_(x)), silicon oxide, a metal oxide, or the like.The adhesive layer 17 may be made of, for example, a thermosetting resinor an ultraviolet curable resin.

The first electrode 12 also functions as a reflective layer, and inorder to improve light emission efficiency, the first electrode 12 maydesirably have as high reflectivity as possible. In particular, in acase where the first electrode 12 is used as an anode, the firstelectrode 12 may be desirably made of a material with a high holeinjection property. As such a first electrode 12, for example, athickness in a laminate direction (hereinafter simply referred to as“thickness”) thereof may be from 100 nm to 1000 nm both inclusive, and asimple substance of a metal element such as chromium (Cr), gold (Au),platinum (Pt), nickel (Ni), copper (Cu), tungsten (W), or silver (Ag),or an alloy thereof may be used. A transparent conductive film such asan oxide of indium and tin (ITO) may be provided on a surface of thefirst electrode 12. It is to be noted that, even a material in whichpresence of oxidized film on a surface and hole injection barrier causedby a small work function cause an issue in spite of high reflectivity isallowed to be used as the first electrode 12 by providing an appropriatehole injection layer.

The insulating film 13 is configured to secure insulation between thefirst electrode 12 and the second electrode 15, and to partition a lightemission region into a desired shape, and may be made of, for example, aphotosensitive resin. The insulating film 13 is provided around thefirst electrode 12, and a region exposed from the insulating film 13 ofthe first electrode 12, i.e., the opening section 13A of the insulatingfilm 13 serves as a light emission region. In this embodiment, asdescribed above, the side surface of the insulating film 13 has aninclination angle, i.e., the reflective surface angle (θ) set for eachof the red pixel 2R, the green pixel 2G, and the blue pixel 2B. It is tobe noted that the organic layer 14 and the second electrode 15 areprovided on the insulating film 13 as well; however, only the lightemission region emits light.

The organic layer 14 may have, for example, a configuration in which ahole injection layer 14A, a hole transport layer 14B, the light-emittinglayer 14C, an electron transport layer 14D, and an electron injectionlayer 14E are laminated in order from the first electrode 12. The layersother than the light-emitting layer 14C may be provided as necessary.The organic layer 14 may have a configuration different for each ofemission colors of the light-emitting devices 10R, 10G, and 10B. Thehole injection layer 14A is a buffer layer to enhance hole injectionefficiency and to prevent leakage. The hole transport layer 14B isconfigured to enhance hole transport efficiency to the light-emittinglayer 14C. The light-emitting layer 14C is configured to emit light bythe recombination of electrons and holes in response to the applicationof an electric field. The electron transport layer 14D is configured toenhance electron transport efficiency to the light-emitting layer 14C.The electron injection layer 14E is configured to enhance electroninjection efficiency.

The hole injection layer 14A of the light-emitting device 10R may have athickness of, for example, 5 nm to 300 nm both inclusive, and may bemade of, for example, a hexaazatriphenylene derivative. The holetransport layer 14B of the light-emitting device 10R may have athickness of, for example, 5 nm to 300 nm both inclusive, and may bemade of bis[(N-naphthyl)-N-phenyl]benzidine (α-NPD). The light-emittinglayer 14C of the light-emitting device 10R may have a thickness of, forexample, 10 nm to 100 nm both inclusive, and may be made of an8-quinolinol aluminum complex (Alq3) mixed with 40 vol % of2,6-bis[4-[N-(4-methoxyphenyl)N-phenyl]aminostyryl]naphthalene-1,5-dicarbonitrile (BSN-BCN). The electron transportlayer 14D of the light-emitting device 10R may have a thickness of, forexample, 5 nm to 300 nm both inclusive, and may be made of Alq3. Theelectron injection layer 14E of the light-emitting device 10R may have athickness of, for example, about 0.3 nm, and may be made of LiF, Li₂O,or the like.

The second electrode 15 may have a thickness of, for example, about 10nm, and may be made of an alloy of aluminum (Al), magnesium (Mg),calcium (Ca), or sodium (Na). In particular, an alloy of magnesium andsilver (an Mg—Ag alloy) may be preferable, since the Mg—Ag alloy hasboth electrical conductivity and small absorption in a thin film.Although a ratio of magnesium to silver in the Mg—Ag alloy is notspecifically limited, the ratio may be preferably within a range ofMg:Ag=20:1 to 1:1 both inclusive in film thickness ratio. Moreover, thematerial of the second electrode 15 may be an alloy of aluminum (Al) andlithium (Li) (an Al—Li alloy).

The second electrode 15 may also function as a semi-transparentreflective layer. In a case where the second electrode 15 has a functionas a semi-transparent reflective layer, the light-emitting device 10Rhas a resonator structure MC1, and the resonator structure MC1 allowslight emitted from the light-emitting layer 14C to be resonated betweenthe first electrode 12 and the second electrode 15. In the resonatorstructure MC1, an interface between the first electrode 12 and theorganic layer 14 serves as a reflective surface P 1, an interfacebetween a middle layer 18 and the electron injection layer 14E serves asa semi-transmissive reflective surface P2, and the organic layer 14serves as a resonating section, and the resonator structure MC1 allowslight emitted from the light-emitting layer 14C to be resonated, andextracts the light from the semi-transmissive reflective surface P2.When the resonator structure MC1 is included, light emitted from thelight-emitting layer 14C causes multiple interference to reduce ahalf-width of a spectrum of light extracted from the semi-transmissivereflective surface P2, thereby increasing peak intensity. In otherwords, light radiant intensity in a front direction is increased toimprove color purity of emission light. Moreover, outside light incidentfrom the sealing substrate 19 is allowed to be attenuated by multipleinterference, and reflectivity of outside light in the light-emittingdevices 10R, 10G, and 10B is allowed to be reduced to an extremely smallvalue by a combination with the color filter 23.

(1-3. Manufacturing Method)

Next, a method of manufacturing the display unit 1A will be describedwith use of FIGS. 8A to 8C and FIG. 9.

First, the pixel drive circuit 140 including the first electrode 12 andthe driving transistor Tr1 is formed on the drive substrate 11 made ofthe above-described material, and then a planarization insulating filmis formed by coating an entire surface of the pixel drive circuit 140with a photosensitive resin. The planarization insulating film ispatterned into a predetermined shape along with formation of theconnection hole through exposure and development, and then is fired.

Next, as illustrated in FIG. 8A, the first electrode 12 made of theabove-described material is formed by, for example, a sputtering method,and the first electrode 12 is selectively removed by wet etching to beseparated for each of the light-emitting devices 10R, 10G, and 10B, andthen an entire surface of the drive substrate 11 is coated with aphotosensitive resin that is to serve as the insulating film 13.

Next, opening sections are provided corresponding to light emissionregions by, for example, a photolithography method, and then thephotosensitive resin is fired to form the insulating film 13. Morespecifically, as illustrated in FIG. 8B, a photomask 2A with lighttransparency different for each of the pixels 2R, 2G, and 2B is formedon the photosensitive resin, and then exposed to light, thereby formingphotoresist patterns 22 with specific inclination angles. It is to benoted that the photomask 2A is formed by coating, for example, a bottomsurface of a glass substrate 21 a with light-blocking resist film 21 band forming slits at predetermined positions. Next, dry etching isperformed with use of the photoresist pattern 22 as a mask to form theinsulating films 13 with reflective surface angles (θ) different fromone another as illustrated in FIG. 8C.

It is to be noted that the photomask 2A in which the predetermined slitsare formed at positions corresponding to the pixels 2R, 2G, and 2B isused here; however, the photomask 2A is not limited thereto, and, forexample, as illustrated in FIG. 9, the insulating film 13 may beprocessed with use of a photomask 21B in which inclination angles are soformed as to obtain predetermined light transparency.

Next, the hole injection layer 14A, the hole transport layer 14B, thelight-emitting layer 14C, and the electron transport layer 14D that aremade of the above-described materials with the above-describedthicknesses of the organic layer 14 are formed by, for example, anevaporation method. Next, the second electrode 15 made of theabove-described material with the above-described thickness is formedby, for example, an evaporation method. Therefore, the light-emittingdevices 10R, 10G, and 10B as illustrated in FIGS. 2 and 5 are formed.

Next, the protective layer 16 made of the above-described material isformed on the light-emitting devices 10R, 10G, and 10B by, for example,a CVD method or a sputtering method. Next, the adhesive layer 17 isformed on the protective layer 16, and the sealing substrate 19including the color filter 18A and the black matrix 18B is bonded ontothe protective layer 16 with the adhesive layer 17 in between. Thus, thedisplay units 1A or 1B illustrated in FIG. 2 or 5 is completed.

In this display unit A, the scanning signal is supplied from thescanning line drive circuit 130 to each pixel 2 through the gateelectrode of the transistor Tr2, and the image signal is supplied fromthe signal line drive circuit 120 to the retention capacitor Cs throughthe writing transistor Tr2 to be retained in the retention capacitor Cs.In other words, on-off control of the transistor Tr1 is performed inresponse to the signal retained in the retention capacitor Cs, and adrive current Id is thereby injected into the light-emitting devices10R, 10G, and 10B to allow the light-emitting devices 10R, 10G, and 10Bto emit light by the recombination of holes and electrons. This light ismultiply-reflected between the first electrode 12 and the secondelectrode 15, or reflected light from the first electrode 12 and lightemitted from the light-emitting layer 14C reinforce each other byinterference, and the light passes through the second electrode 15, thecolor filter 23, and the sealing substrate 19 to be extracted.

(1-4. Functions and Effects)

In this embodiment, the side surface of the insulating film 13 thatseparates the respective sub-pixels 2R, 2G, and 2B from one anotherserves as a reflective surface with respect to light emitted from thelight-emitting layer 14C, and the angle (the reflective surface angle(θ)) of the reflective surface is set for each of the sub-pixels 2R, 2G,and 2B. The insulating film 13 having the reflective surface angle (θ)different for each of the sub-pixels 2R, 2G, and 2B is allowed to beformed by performing photolithography using a photomask withpredetermined light transparency at a position corresponding to each ofthe pixels 2R, 2G, and 2B. Therefore, in particular, emission light withhigh light emission intensity of which the emission direction differsaccording to each wavelength of emission light of each of thelight-emitting devices 10R, 10G, and 10B is allowed to be reflected inan arbitrary direction. More specifically, emission light with highlight emission intensity from the sub-pixels 2R, 2G, and 2B is reflectedto substantially the same direction.

Thus, in the display unit 1A and the method of manufacturing the same inthis embodiment, an inclined surface (the side surface) of theinsulating film 13 that partitions the sub-pixels 2R, 2G, and 2B andserves as the reflective surface with respect to emission light from thelight-emitting layer 14C is formed by photolithogprahy using a photomaskwith predetermined light transparency. Therefore, the inclined surfacehaving a reflection angle different for each of the pixels 2R, 2G, and2B is allowed to be easily formed. In other words, the inclined surfacesof the insulating films 13 of the respective sub-pixels 2R, 2G, and 2Bare allowed to be formed separately at angles suitable for the emissionlight LR, LG, and LB of the light emitting devices 10R, 10G, and 10B,respectively, more specifically at angles (the reflective surface angles(θ)) at which emission light with high light emission intensitydifferent for each wavelength in the sub-pixels 2R, 2G, and 2B isallowed to be reflected to substantially the same reflection direction.Accordingly, the occurrence of the color shift in the sub-pixels 2R, 2G,and 2B is suppressed, and color reproductivity is improved.

Moreover, emission light with high light emission intensity is allowedto be used efficiently; therefore, variation in luminance of each of thesub-pixels 2R, 2G, and 2B is suppressed, and luminance is improved.Further, since light emission efficiency is improved, a display unitwith low power consumption is allowed to be provided.

4. MODIFICATION EXAMPLES

Modification examples of the above-described embodiment will bedescribed below. In the following description, like components aredenoted by like numerals as of the above-described embodiment and willnot be further described.

Modification Example 1

FIG. 10A schematically illustrates a sectional configuration of a pixel4 (sub-pixels 4R, 4G, and 4B) configuring a display unit IC according toModification Example 1, and FIG. 10B schematically illustrates lightemission regions of the respective sub-pixels 4R, 4G, and 4B, i.e.,sizes of openings of opening sections 13AR, 13AG, and 13AB. This displayunit 1C has a configuration similar to those of the above-describeddisplay units 1A and 1B, except that the aperture ratios of the lightemission regions of the light-emitting devices 10R, 10G, and 10B, i.e.,the opening sections 13AR, 13AG, and 13AB of the pixels 4R, 4G, and 4Bare different from one another.

In outputs of the respective pixels 4R, 4G, and 4B, the output of theblue pixel 4B is typically high, and the output of the red pixel 4R istypically low. This is caused by properties of materials forming thelight-emitting layers 14CR, 14CG, and 14CB of the light-emitting devices10R, 10G, and 10B. In a display unit having an output different for eachof the pixels 4R, 4G, and 4B, variation in color reproductivity, i.e.,so-called coloring may be caused by the viewing angle.

On the other hand, in this modification example, the aperture ratios ofthe opening sections 13AR, 13AG, and 13AB of the insulating film 13 areadjusted for each pixel. More specifically, for example, based on theopening section 13AG of the green pixel 4G, the opening section 13AR ofthe insulating film 13 in the red pixel 4R is increased in size, and theopening section 13AB of the insulating film 13 in the blue pixel 4B isdecreased in size. In other words, as illustrated in FIG. 10B, theaperture ratios of the red pixel 4R, the green pixel 4G, and the bluepixel 4B are made smaller (the light emission regions are made narrower)in this order. The light emission levels of RGB are made uniform bymaking luminances in the pixels 4R, 4G, and 4B uniform in such a manner,thereby suppressing coloring by the viewing angle.

Modification Example 2

FIG. 11 schematically illustrates other examples of pixel shapes of thepixels 2 to 4 configuring the above-describe display units 1A to 1C. Inthe above-described embodiment and the above-described ModificationExample 1, a case where the shape of the pixel 2, i.e., the lightemission region is circular is described; however, the shape is notlimited thereto. For example, the shape may be oval as illustrated inFIG. 11(A), rectangular as illustrated in FIGS. 11(B) and (C), orsubstantially rectangular as illustrated in FIG. 11(D). In the circularshape as with the above-described embodiment, respective pixels arearranged in dots; however, in a case where the pixel 2 has a verticallylong rectangular shape as illustrated in FIG. 11(C), for example, asillustrated in FIG. 12, the pixels may be arranged in a matrix.

Modification Example 3

It is to be noted that in the insulating film 13 configuring theabove-described display units 1A to 1C, in addition to designing thereflective surface angle (θ) for each of the sub-pixels 2R, 2G, and 2B,the constituent material of the insulating film may be changed. Forexample, an insulating film may be formed with use of materials withdifferent refractive indices, thereby adjusting the emission directionof the emission light from each of the light-emitting layers 14CR, 14CG,and 14CB.

The materials with different refractive indices may include thefollowing materials. Examples of a material with a high refractive indexmay include silicon nitride (Si₃N₄), aluminum oxide (Al₂O₃), chromiumoxide (Cr₂O₃), gallium oxide (Ga₂O₃), hafnium oxide (HfO₂), nickel oxide(NiO), magnesium oxide (MgO), indium tin oxide (ITO), lanthanum oxide(La₂O₃), niobium oxide (Nb₂O₅), tantalum oxide (Ta₂O₅), yttrium oxide(Y₂O₃), tungsten oxide (WO₃), titanium monoxide (TiO), titanium dioxide(TiO₂), and zirconium oxide (ZrO₂). Examples of a material with a lowrefractive index may include silicon oxide (SiO₂), aluminum fluoride(AlF₃), calcium fluoride (CaF₂), cerium fluoride (CeF₃), lanthanumfluoride (LaF₃), lithium fluoride (LiF), magnesium fluoride (MgF₂),neodymium fluoride (NdF₃), and sodium fluoride (NaF).

Examples of a specific combination may include a combination of siliconnitride (Si₃N₄) and silicon oxide (SiO₂).

3. EXAMPLES

Examples according to the display unit of the present disclosure will bedescribed below.

Example 1

In this example, as a standard sample, the display unit 1A with a pixelconfiguration described in the above-described embodiment wasfabricated. More specifically, in the light-emitting devices 10R, 10G,and 10B, film thicknesses of respective layers including thelight-emitting layer 14C were equal in the sub-pixels 2R, 2G, and 2B.Under this condition, a sample 1 (a comparative example) and a sample 2(the example) were fabricated. In the sample 1, the reflective surfaceangle (θ) of the insulating film 13 was equal in the pixels 2R, 2G, and2B, and in the sample 2 (the example), the reflective surface angle (θ)of the insulating film 13 was adjusted for each of the sub-pixels 2R,2G, and 2B, and more specifically, the reflective surface angle (θ) ofthe insulating film 13 in the green pixel 2G was 70°, and the reflectivesurface angle (θ) in the red pixel 2R and the blue pixel 2B was 80°.Luminance at each viewing angle of each of the sample 1 and the sample 2was measured.

FIGS. 13A and 13B are characteristic diagrams illustrating arelationship between the viewing angle and luminance (intensity) in thesamples 1 and 2, respectively. It was found that in FIG. 13A, variationbetween green emission light, and red emission light and blue emissionlight was large, and in FIG. 13B, the values of luminance at eachviewing angle in the pixels 2R, 2G, and 2B were substantially equal.Moreover, compared to FIG. 13A, it was found that the luminance at aviewing angle of 0° was greatly improved.

Example 2

This example differs from the above-described example in that thethickness of the first electrode 12 was changed for each light-emittingdevice. FIG. 14A is a characteristic diagram illustrating a relationshipbetween a viewing angle and luminance of a sample 3 as a comparativeexample, and FIG. 14B is a characteristic diagram illustrating arelationship between a viewing angle and luminance of a sample 4 as theexample. It is to be noted that the reflective surface angles (θ) of theinsulating films 13 in the pixels 2R, 2G, and 2B of the sample 4 were80°, 70°, and 70°, respectively.

As can be seen from FIG. 14A, improved luminance was obtained byadjusting the film thickness of the first electrode 12 for each of thepixels 2R, 2G, and 2B; however, variation in luminance at viewing anglesbetween the pixels 2R, 2G, and 2B was noticeable. On the other hand, ascan be seen from FIG. 14B, as with the sample 2 of the above-describedexample 1, the values of luminance at each viewing angle in thesub-pixels 2R, 2G, and 2B were substantially equal.

Example 3

This example differs from the above-described example in that the filmthickness of the light-emitting layer 14C was changed. FIG. 15A is acharacteristic diagram illustrating a relationship between a viewingangle and luminance of a sample 5 as a comparative example, and FIG. 15Bis a characteristic diagram illustrating a relationship between aviewing angle and luminance of a sample 6 as an example. It is to benoted that the reflective surface angles (θ) of the insulating films 13in the pixels 2R, 2G, and 2B of the sample 6 were 70°, 70°, and 80°,respectively.

As can be seen from FIG. 15A, compared to the sample 1, improvedluminance was obtained by adjusting the film thickness of the organiclayer 14 for each of the pixels 2R, 2G, and 2B; however, variation inluminance at viewing angles between the pixels 2R, 2G, and 2B wasnoticeable. On the other hand, as can be seen from FIG. 14B, as with thesamples 2 and 4 of the above-described example 1, the values ofluminance at each viewing angle in the sub-pixels 2R, 2G, and 2B weresubstantially equal.

As can be seen from Examples 2 and 3, even if the thicknesses of thefirst electrodes 12 or the like of the light-emitting devices 10R, 10G,and 10B are changed for respective sub-pixels, the color shift by theviewing angle is allowed to be reduced.

Example 4

In this example (a sample 7), the size of the light emission of thesample 6 was adjusted for each pixel. More specifically, in the sample6, the size of the light emission region of the red pixel 2R wasincreased by 3%, and the size of the light emission region of the bluepixel 2B was decreased by 3%. FIG. 16 is a characteristic diagramillustrating a relationship between a viewing angle and luminance of thesample 7.

As can be seen from FIG. 16, the color shift by the viewing angles ineach of the pixels 2R, 2G, and 2B is reduced by adjusting not only thereflective surface angle (θ) of the insulating film 13 but also thelight emission region for each of the pixels 2R, 2G, and 2B, therebyachieving optimization.

4. APPLICATION EXAMPLES

The display units 1A to 1C including the pixels 2 to 4 described in theabove-described embodiment and the above-described Modification Examples1 to 3 may be preferably used specifically for a finder of a camera anda display unit of a head mounted display, and may be mounted inelectronic apparatuses in any fields that display an image (or apicture), for example, the following electronic apparatuses.

FIGS. 17A and 17B illustrate an appearance of a smartphone. Thissmartphone may include, for example, a display section 110 (the displayunit A), a non-display section (an enclosure) 120, and an operationsection 130. The operation section 130 may be disposed on a frontsurface or a top surface of the non-display section 120.

FIG. 18 illustrates an appearance configuration of a television. Thistelevision may include, for example, an image display screen section 200(the display unit A) including a front panel 210 and a filter glass 220.

FIGS. 19A and 19B illustrate appearance configurations of a frontsurface and a back surface of a digital still camera, respectively. Thisdigital still camera may include, for example, a light-emitting section310 for a flash, a display section 320 (the display unit A), a menuswitch 330, and a shutter button 340.

FIG. 20 illustrates an appearance configuration of a notebook personalcomputer. This personal computer may include, for example, a main body410, a keyboard 420 for operation of inputting characters and the like,and a display section 430 (the display unit A) that displays an image.

FIG. 21 illustrates an appearance configuration of a video camera. Thisvideo camera may include, for example, a main body section 510, a lens520 provided on a front side surface of the main body section 510 andfor shooting an image of a subject, a shooting start and stop switch530, and a display section 540 (the display unit A).

FIGS. 22A and 22B illustrate an appearance configuration of a mobilephone. FIG. 19A illustrates a front surface, a left side surface, aright side surface, a top surface, and a bottom surface in a state inwhich the mobile phone is closed. FIG. 19B illustrates a front surfaceand a side surface in a state in which the mobile phone is opened. Thismobile phone may have a configuration in which, for example, a top sideenclosure 610 and a bottom-side enclosure 620 are connected togetherthrough a connection section (hinge section) 620, and the mobile phonemay include a display 640 (the display units 1A to 1C), a sub-display650, a picture light 660, and a camera 670.

Although the present disclosure is described referring to the embodimentand Modification Examples 1 to 3, the present disclosure is not limitedthereto, and may be variously modified. For example, the material andthickness of each layer, the method and conditions of forming each layerare not limited to those described in the above-described embodiment andthe like, and each layer may be made of any other material with anyother thickness by any other method under any other conditions.

Moreover, all of the respective layers described in the above-describedembodiment and the like may not be necessarily included, and one or moreof them may be omitted as necessary. Further, a layer other than thelayers described in the above-described embodiment and the like may beadded. For example, one or more layers using a material having holetransport capability such as a common hole transport layer described inJapanese Unexamined Patent Application Publication No. 2011-233855 maybe added between a charge transport layer 17 and the blue light-emittinglayer 14CB of the blue light-emitting device 10B. When such a layer isadded, light emission efficiency and lifetime characteristics of theblue light-emitting device 10B are improved.

Furthermore, in the above-described embodiment and the like, a casewhere the sub-pixels configuring one pixel include three pixels, i.e.,the red pixel, the green pixel, and the blue pixel is described as anexample; however, a white pixel or a yellow pixel may be added inaddition to the three sub-pixels.

It is to be noted that the present technology is allowed to havefollowing configurations.

(1) A display unit including:

a plurality of pixels configured to emit emission light different fromone another; and

an insulating film provided between the plurality of pixels and having areflective surface with respect to the emission light,

in which an angle of the reflective surface of the insulating film isset for each of the pixels.

(2) The display unit according to (1), in which a red pixel, a greenpixel, and a blue pixel are included, and the reflective surface angles(θ) for the red pixel, the green pixel, and the blue pixel are differentfrom each other.

(3) The display unit according to (1) or (2), in which a first pixelincluding a red pixel, a green pixel, or a blue pixel and a second pixelof a color different from the first pixel, and the reflective surfaceangle (θ) of the first pixel is different from that of the second pixel.

(4) The display unit according to any one of (1) to (3), in which thereflective surface angle (θ) is determined with use of an angle (ϕ) atwhich light emission intensity of the emission light is strong.

(5) The display unit according to any one of (1) to (4), in which theplurality of pixels have different aperture ratios from one another.

(6) The display unit according to any one of (1) to (5), in which areflective surface of the insulating film has a refractive indexdifferent for each of the plurality of pixels.

(7) A method of manufacturing a display unit including:

arranging a plurality of pixels configured to emit emission lightdifferent from one another; and

forming, between the plurality of pixels, an insulating film having areflective surface with respect to the emission light and in which anangle of the reflective surface is set for each of the pixels.

(8) The method of manufacturing the display unit according to (7), inwhich the angle of the reflective surface of the insulating film isadjusted with use of photolithography using of a photomask having lighttransmittance varying in a stepwise manner.

(9) An electronic apparatus provided with a display unit, the displayunit including:

a plurality of pixels configured to emit emission light different fromone another; and

an insulating film provided between the plurality of pixels and having areflective surface with respect to the emission light,

in which an angle of the reflective surface of the insulating film isset for each of the pixels.

It should be understood by those skilled in the art that variousmodifications, combinations, sub-combinations, and alterations may occurdepending on design requirements and other factors insofar as they arewithin the scope of the appended claims or the equivalents thereof.

The invention claimed is:
 1. A display unit, comprising: a drivesubstrate, and a plurality of light emitting elements provided on thedrive substrate, wherein the light emitting elements include a firstlight emitting element including a first anode electrode and a cathodeelectrode, a second light emitting element including a second anodeelectrode and the cathode electrode, and a third light emitting elementincluding a third anode electrode and the cathode electrode, the firstlight emitting element includes a first light emission region, thesecond light emitting element includes a second light emission region,and the third light emitting element includes a third light emissionregion, an insulating film comprises a first portion and a secondportion, the first portion is located between the first anode electrodeand the second anode electrode, the second portion is located betweenthe second anode electrode and the third anode electrode, a shape of thefirst portion is different from a shape of the second portion in a crosssectional view, and a thickness from a bottom surface of the firstportion to a top surface of the first portion is thicker than athickness of the first anode electrode, and a thickness from a bottomsurface of the second portion to a top surface of the second portion isthicker than a thickness of the second electrode.
 2. The display unitaccording to claim 1, further comprising a color filter associated withthe light emitting devices.
 3. The display unit according to claim 1,further comprising a light blocking layer configured to block light fromthe light emitting devices.
 4. The display unit according to claim 3,wherein the light blocking layer includes a black matrix associated withthe light emitting devices.
 5. The display unit according to claim 4,wherein the black matrix is provided at a light emission direction. 6.The display unit according to claim 1, wherein each of the first,second, and third light emitting devices includes an organic layer. 7.The display unit according to claim 1, wherein the first light emittingdevice is configured to emit light corresponding to a first color, thesecond light emitting device is configured to emit light correspondingto a second color, and the third light emitting device is configured toemit light corresponding to a third color.
 8. The display unit accordingto claim 7, wherein the first color, the second color, and the thirdcolor are different.
 9. The display unit according to claim 1, whereinthe drive substrate includes a pixel control circuit, and wherein thepixel control circuit includes a driving transistor, a writingtransistor and a capacitor.
 10. The display unit according to claim 1,further comprising a sealing layer configured to seal the light emittingdevices.
 11. The display unit according to claim 1, wherein the drivesubstrate includes a drive circuit configured to control the lightemitting devices.
 12. The display unit according to claim 1, wherein theinsulating film has a reflective surface with respect to emission lightof the first, second, and third light emitting elements.
 13. The displayunit according to claim 12, wherein the reflective surface angle (θ) isdetermined with use of an angle (ϕ) at which light emission intensity ofthe emission light is above a first level.
 14. The display unitaccording to claim 1, wherein a first pixel includes the first lightemission region and a second pixel includes the second light emissionregion, and the first pixel and the second pixel have different apertureratios from one another.
 15. The display unit according to claim 1,wherein a top surface of the insulating film has asperities or a curvedsurface.
 16. An electronic apparatus comprising a display unit, whereinthe display unit comprises: a drive substrate, and a plurality of lightemitting elements provided on the drive substrate, wherein the lightemitting elements include a first light emitting element including afirst anode electrode and a cathode electrode, a second light emittingelement including a second anode electrode and the cathode electrode,and a third light emitting element including a third anode electrode andthe cathode electrode, the first light emitting element includes a firstlight emission region, the second light emitting element includes asecond light emission region, and the third light emitting elementincludes a third light emission region, an insulating film comprises afirst portion and a second portion, the first portion is located betweenthe first anode electrode and the second anode electrode, the secondportion is located between the second anode electrode and the thirdanode electrode, a shape of the first portion is different from a shapeof the second portion in a cross sectional view, and a thickness from abottom surface of the first portion to a top surface of the firstportion is thicker than a thickness of the first anode electrode, and athickness from a bottom surface of the second portion to a top surfaceof the second portion is thicker than a thickness of the secondelectrode.